Unit 6- Topic 5

Question 1

Operons

Answer 1

A group of genes that can be turned on or off

Question 2

Promoter

Answer 2

Where RNA Polymerase can attach

Question 3

Operator

Answer 3

The on/off switch

Question 4

Genes

Answer 4

Code for related enzymes in pathway

Question 5

Apoptosis

Answer 5

Programmed cell death

Question 6

Operons can be either

Answer 6

repressible or inducible

Question 7

Repressible

Answer 7

transcription on to off

Question 8

Inducible

Answer 8

transcription off to on

Question 9

Allosteric Activator

Answer 9

substrate binds to allosteric site and stabilizes the shape of the enzyme so that the active sites remain open (active form).

Question 10

Allosteric Inhibitor

Answer 10

substrate binds to allosteric site & stabilizes the enzyme shape so that the active sites are closed (inactive form).

Question 11

Histone acetylation

Answer 11

adds acetyl groups to histones, which loosens the dna

Question 12

dna methylation

Answer 12

adds methyl groups to DNA, which causes the chromatin to condense

Question 13

Differentiation

Answer 13

cells become specialized in their structure and function

Question 14

Morphogenesis

Answer 14

the physical process that gives an organism its shape

Question 15

Cytoplasmic determinant

Answer 15

substances in the maternal egg that influence cells

Question 16

Induction

Answer 16

cell to cell signals that can cause a change in gene expression

Question 17

Pattern formation

Answer 17

a “body plan” for the organism

Question 18

Homeotic genes

Answer 18

map out the body structures

Question 19

Epigenetic inheitance

Answer 19

chromatin modifications do not alter the nucleotide sequence of the DNA, but they can be heritable to future generations.

modifications can be reversed, unlike mutations.

why 1 twin can inherit a disease and the other does not.

Question 20

Regulatory gene

Answer 20

produces a repressor protein that binds to the operator to block RNA polymerase from transcribing the gene.

expressed low levels
binding of a repressor to an operator is reversible